title: The calcium silicate/alginate composite: preparation and evaluation of its behavior as bioactive injectable hydrogels.
abstract: In this study, an injectable calcium silicate (CS)/sodium alginate (SA) hybrid hydrogel was prepared using a novel material composition design. CS was incorporated into an alginate solution and internal in situ gelling was induced by the calcium ions directly released from CS with the addition of d-gluconic acid δ-lactone (GDL). The gelling time could be controlled, from about 30s to 10 min, by varying the amounts of CS and GDL added. The mechanical properties of the hydrogels with different amounts of CS and GDL were systematically analyzed. The compressive strength of 5% CS/SA hydrogels was higher than that of 10% CS/SA for the same amount of GDL. The swelling behaviors of 5% CS/SA hydrogels with different contents of GDL were therefore investigated. The swelling ratios of the hydrogels decreased with increasing GDL, and 5% CS/SA hydrogel with 1% GDL swelled by only less than 5%. Scanning electron microscopy (SEM) observation of the scaffolds showed an optimal interconnected porous structure, with the pore size ranging between 50 and 200 μm. Fourier transform infrared spectroscopy and SEM showed that the CS/SA composite hydrogel induced the formation of hydroxyapatite on the surface of the materials in simulated body fluid. In addition, rat bone mesenchymal stem cells (rtBMSCs) cultured in the presence of hydrogels and their ionic extracts were able to maintain the viability and proliferation. Furthermore, the CS/SA composite hydrogel and its ionic extracts stimulated rtBMSCs to produce alkaline phosphatase, and its ionic extracts could also promote angiogenesis of human umbilical vein endothelial cells. Overall, all these results indicate that the CS/SA composite hydrogel efficiently supported the adhesion, proliferation and differentiation of osteogenic and angiogenic cells. Together with its porous three-dimensional structure and injectable properties, CS/SA composite hydrogel possesses great potential for bone regeneration and tissue engineering applications.
authors.affiliation: Med-X Research Institute, Department of Biomedical Engineering, Shanghai Jiaotong University, 1954 HuaShan Road, Shanghai 200030, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Han
authors.forename: Qiongyu
authors.initials: Q
authors.lastname: Zeng
authors.forename: Haiyan
authors.initials: H
authors.lastname: Li
authors.forename: Jiang
authors.initials: J
authors.lastname: Chang
mesh_terms: D000464:Alginates / Q000494:pharmacology*; D000818:Animals; D001672:Biocompatible Materials / Q000494:pharmacology*; D017610:Calcium Compounds / Q000494:pharmacology*; D002454:Cell Differentiation / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D019245:Compressive Strength / Q000187:drug effects; D020405:Dermis / Q000166:cytology; D005347:Fibroblasts / Q000166:cytology / Q000187:drug effects; D020723:Glucuronic Acid / Q000494:pharmacology; D006603:Hexuronic Acids / Q000494:pharmacology; D061307:Human Umbilical Vein Endothelial Cells / Q000166:cytology / Q000187:drug effects; D006801:Humans; D020100:Hydrogels / Q000494:pharmacology*; D007267:Injections; D007477:Ions; D007783:Lactones / Q000737:chemistry; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D018919:Neovascularization, Physiologic / Q000187:drug effects; D010012:Osteogenesis / Q000187:drug effects; D051381:Rats; D017640:Silicates / Q000494:pharmacology*; D017550:Spectroscopy, Fourier Transform Infrared; D013997:Time Factors; D054457:Tissue Scaffolds / Q000737:chemistry*
chemical_list: D000464:Alginates; D001672:Biocompatible Materials; D017610:Calcium Compounds; D006603:Hexuronic Acids; D020100:Hydrogels; D007477:Ions; D007783:Lactones; D017640:Silicates; D020723:Glucuronic Acid; C031293:calcium silicate
keywords: Alginate; Calcium silicate; Hydrogel; Injectable; Tissue engineering